Studies On Synthesis Of Nitriles,Indoleisoquinolinones And ?-Selenoenals/-enones Under Aerobic Conditions

Molecular oxygen is widely used as an ideal oxidant in oxidation reactions due to its abundant nature,environmentally friendly,non-polluting,easy to operate,and cheap characteristics.In recent years,visible-light-induced catalytic systems have been widely used in aerobic oxidation reactions as a new strategy.In addition,visible-light-driven aerobic oxidation reaction under mild,efficient,and environmentally benign reaction conditions has become a powerful tool to promote the formation of new chemical bonds.This thesis introduces the recent advances in this research area of visible-light-driven aerobic oxidation reactions involving thiocyanate salts,and C-H bond activation through merging photocatalysis and transition metal cobalt catalysis in catalytic aerobic oxidation;the related visible-light-catalyzed aerobic oxidation reactions were investigated.Additionally,we also studied the Meyer-Schuster rearrangement reaction by using Selectfluor and diselenides in-situ generated electrophilic selenium species.The details are as follows:1.Dehydration reaction of aldoximes mediated by thiocyanate anion in visible light and air.Under visible light irradiation and metal-free conditions,with a catalytic amount of organic dye aizenuranine as the photocatalyst,a new means of activating aldoximes was developed by an in situ generated thiocyanate radical from ammonium thiocyanate and air at room temperature.This strategy provided a facile protocol for the synthesis of a series of nitrile compounds with inexpensive and easily accessible materials,neutral and mild reaction conditions,a simple to handle,wide substrate,outstanding functional group tolerance.Furthermore,the reaction mechanism was studied by free radical intermediate trapping experiments,GC-MS experiments,electrochemical experiments,ESR experiments and DFT calculations.2.[4+2]Annulation of arylamides and indole derivatives through merging photocatalysis and transition metal cobalt catalysis.Indolo[2,3-c]isoquinolin-5-ones also known as benzopyridoindolones,as a kind of core skeletons widely exists in many natural products,drugs,and compounds with biomedical activity.The efficient construction of indolo[2,3-c]isoquinolin-5-ones has attracted much research interest from chemists.We realized the[4+2]annulation of arylamide and indole derivatives using air as oxidant by combining visible light and metal cobalt dual catalysis and provides a mild,straightforward,high step-and atom-economical approach to producing a diverse array of indolo[2,3-c]isoquinolin-5-ones.A catalytically competent organometallic Co(bzac)₃has been identified through X-ray crystallography,¹H NMR,¹³C NMR,and ESI-HRMS.We have studied the reaction mechanism via radical trap experiments,KO₂ experiment,H/D exchange experiment,and KIE experiments(parallel and competition).3.Selenenylation and Meyer-Schuster rearrangement of propargyl alcohols:Synthesis of?-selenoenals and-enones.?-Selenoenals and-enones have immunomodulatory and antioxidant properties.We developed the selenenylation and Meyer-Schuster rearrangement reaction of propargyl alcohols.This reaction uses Selectfluor and diselenides in-situ generated electrophilic selenium species to activate the carbon-carbon triple bond of propargyl alcohols,resulting in a series of multi-substituted?-selenoenals/ketones in a simple,efficient,and high atom economy under neutral conditions at room temperature.In addition,we also realized the selenenylation and cyclization reaction of o-alkynyl aniline and 2-alkynyl phenols.